Sirinakis George, Siddique Rezina, Manning Ian, Rogers Phillip H, Carpenter Michael A
College of Nanoscale Science and Engineering, The University at Albany-State University of New York, 255 Fuller Road, Albany, New York 12203, USA.
J Phys Chem B. 2006 Jul 13;110(27):13508-11. doi: 10.1021/jp062760n.
Au-YSZ nanocomposite films exhibited a surface plasmon resonance absorption band around 600 nm that underwent a reversible blue shift and narrowed upon exposure to CO in air at 500 degrees C. A linear dependence of the sensing signal was observed for CO concentrations ranging between 0.1 and 1 vol % in an air carrier gas. This behavior of the SPR band, upon exposure to CO, was not observed when using nitrogen as the carrier gas, indicating an oxygen-dependent reaction mechanism. Additionally, the SPR band showed no measurable signal change upon exposure to CO at temperatures below approximately 400 degrees C. The oxygen and temperature-dependent characteristics, coupled with the oxygen ion formation and conduction properties of the YSZ matrix, are indicative of charge-transfer reactions occurring at the three-phase boundary region between oxygen, Au, and YSZ, which result in charge transfer into the Au nanoparticles. These reactions are associated with the oxidation of CO and a corresponding reduction of the YSZ matrix. The chemical-reaction-induced charge injection into the Au nanoparticles results in the observed blue shift and narrowing of the SPR band.
金-钇稳定氧化锆（Au-YSZ）纳米复合薄膜在600纳米左右呈现出表面等离子体共振吸收带，在500摄氏度的空气中暴露于一氧化碳时，该吸收带会发生可逆的蓝移并变窄。在空气载气中，当一氧化碳浓度在0.1%至1%（体积）之间时，观察到传感信号呈线性依赖关系。当使用氮气作为载气时，暴露于一氧化碳时未观察到表面等离子体共振（SPR）带的这种行为，这表明反应机制依赖于氧气。此外，在低于约400摄氏度的温度下暴露于一氧化碳时，SPR带未显示出可测量的信号变化。氧气和温度依赖性特征，再加上钇稳定氧化锆（YSZ）基体的氧离子形成和传导特性，表明在氧气、金和YSZ之间的三相边界区域发生了电荷转移反应，这导致电荷转移到金纳米颗粒中。这些反应与一氧化碳的氧化以及YSZ基体的相应还原有关。化学反应诱导的电荷注入到金纳米颗粒中导致了观察到的SPR带的蓝移和变窄。
